The United States Embassy in Jakarta has warned Americans that an attack may occur on the resort island of Bali on New Year's Eve.

According to the U.S. Embassy in Jakarta, a message from Bali's provincial governor says that "there is an indication of an attack to Bali tonight." The embassy says the governor goes on to say, "please don't panic, but put your security system to full alert."

But some news agencies report that the governor's office denies posting any such warning.

"One of the most important things the U.S. Embassy does here in Indonesia is to take care of the security of American citizens here in Indonesi," said Sanders. "And we are reporting what we learned from the Bali tourism board, according to the governor of Bali and it concerns the safety and security of American citizens and we wanted to immediately share that information because we want everyone to have a safe and happy New Year's Eve."

While there are no details about the source or the credibility of the threat, Sanders recommends that tourists in Bali, especially Americans, take precautions.

"We urge them to monitor local news reports and maintain a low profile and vary their route and times and just be very, very security and safety conscious," she said.

The warning in Bali follows a failed terrorist attack on a plane flying into the American city of Detroit last week. Al-Qaida has taken credit for the bombing attempt.

The U.S. Embassy in Jakarta posted the travel warning on its Web site and reminds visitors that Jemaah Islamiyah, an Indonesian terrorist organization affiliated with al Qaida, remains an active threat.

Suspected JI members bombed two Western-owned hotels in Jakarta in July, killing nine Indonesians and foreigners and injuring over 50.

The travel warning says "U.S. citizens in Indonesia must be physically and mentally prepared to cope with future attacks even as they go about their normal daily routines."

Twice before, Bali has seen devastating terrorist attacks. More than 200 people, Indonesians and foreign tourists, were killed in bombings on popular restaurants and bars in 2002 and 2005. Most of the people convicted in those attacks were allied with Jemaah Islamiyah, which wants to create an Islamic state across much of Southeast Asia.